Mobile terminals such as computer and mobile phone, via which information sources are accessed, are developing. As touch screens are easy to use, robust, durable and space saving and have a rapid response speed, system designers are increasingly aware that utilization of touch screens can result in considerable advantages.
With the success of capacitive touch screens, human-machine interactions need to be implemented with a touch control function of a display. In order to achieve the touch function of the display with lower cost and with more convenience, the industry is continually seeking the best solution for integrating display with touch. As the capacitive touch screen technology matures, development space of the capacitive touch screen technology is limited. Gradually, optical touch screen technology has become a focus in the research.
An infrared touch screen is a common optical touch screen, which detects and locates a touch location of a user with an infrared matrix densely arranged in X and Y directions. As shown in FIG. 1, for a conventional infrared touch screen, a circuit board frame is arranged in front of a display, and infrared emitting elements 11 and infrared receiving elements 12 are arranged around the screen in the circuit board. Since the infrared emitting elements 11 and the infrared receiving elements 12 are in a one-to-one correspondence, an infrared matrix is formed in which rays can cross each other horizontally and vertically. When a user touches the screen, a finger blocks a horizontal infrared ray and a vertical infrared ray which pass a touch location 13. In this case, a location of a touch point on the screen can be determined. Any touching object may realize a touch operation by changing infrared rays which pass a touch point.
The inventors found that, while the infrared touch screen technology has been available for a long period of time, the development of infrared touch technology is affected by a large size and a high manufacture cost of the infrared touch screen.